This invention is directed to an improved valve arrangement for selectively distributing fluids from a plurality of supply vessels to a receiving vessel. This invention represents an improvement upon the valve arrangement disclosed in our U.S. Pat. No. 4,008,736; the disclosure of which is hereby incorporated by reference, as if fully set forth herein. Such valve arrangements are utilized in connection with the distribution of chemicals into process vessels for their reaction. It is imperative that the supply lines and conduit lines leading to the vessel remain free from residue and that the valves critically meter the amount of chemicals supplied. The instant invention provides for a valve arrangement that is both mechanically simple and provides for shorter switching times than those of other such arrangements.